Ruthenium(II)-catalyzed sp3 C-H bond arylation of benzylic amines using aryl halides

Abstract

A ruthenium(II)-catalyzed protocol for the direct arylation of benzylic amines was developed. Employing 3-substituted pyridines as directing groups, arylation was achieved using aryl bromides or aryl iodides as the aryl source. Potassium pivalate proved to be an important additive in this transformation. The arylation took place selectively in the benzylic sp(3) position, and no significant competitive sp(2) arylation was observed. Arylated imines were observed as byproducts in minor amounts. Additionally, reaction conditions for cleaving the pyridine group were established, enabling access to bis-arylated methylamines.